Process for producing dielectric insulating thin film, and dielectric insulating material

1. A method for producing a dielectric insulating thin film, comprising: a step (A) of making a substrate having a hydroxyl group in its surface or having a hydroxyl group introduced into its surface, adsorb a metal compound having a functional group capable of reacting with a hydroxyl group for condensation and capable of forming a hydroxyl group through hydrolysis, a step (B) of removing the excessive metal compound from the substrate surface, a step (C) of hydrolyzing the metal compound to thereby form a metal oxide layer having a hydroxyl group in the surface thereof, a step (D) of treating the above-mentioned layer according to any one treating method selected from the group consisting of oxygen plasma treatment, ozone oxidation treatment, firing treatment and rapid thermal annealing treatment to thereby obtain a dielectric insulating thin film; and which further comprises, between the step (C) and the step (D), a step (G) of making the hydroxyl group in the surface of the metal oxide layer formed in the step (C) adsorb a rare earth metal ion, and a step (H) of removing the excessive rare earth metal ion from the surface of the metal oxide layer and hydroxylating the adsorbed rare earth metal ion to thereby form a rare earth metal layer.

2. The production method as claimed in claim 1 , wherein the steps (A) to (C) as well as the steps (G) and (H) are repeated at least once between the step (C) and the step (D) to thereby form at least two layers of metal oxide layer and/or rare earth metal layer.